Turbo-lag compensation system for an engine

ABSTRACT

A boost system for an engine, comprising an engine having at least a cylinder; a fuel injector coupled to said cylinder; a compression device coupled to said engine; a compressed air storage device coupled to said compression device and configured to deliver compressed air to an air flow amplifier device located in the inlet air passageway to said cylinder; and a controller to adjust an amount of fuel injection to account for variation of air delivered to said cylinder from said flow amplifier device.

BACKGROUND AND SUMMARY

Engines may use boosting devices, such as turbochargers, to increaseengine power density. Thus, under steady state operation, smallerdisplacement, turbocharged engines can produce power equivalent tolarger displacement engines. However, under dynamic driving conditions,the smaller turbocharged engine may have less transient performance thana larger, naturally aspirated engine.

As one example, when a turbocharged engine is operating at low load, theturbocharger speed is low and intake manifold pressure is low. When theengine load is suddenly increased, there may be a lag before theturbocharger speed increases and intake manifold pressure rises. Thisdelay may be referred to as “turbo-lag.” During this delay, the enginepower or torque output may be less than desired value, and less than thesteady state available output.

One approach that attempted to provide intake manifold pressure boostwith minimal delay is described in SAE paper 670109, published in 1967.This system used storage tanks to store compressed air with acarbureted, otherwise naturally aspirated gasoline engine. In thissystem, when the system was actuated, desired boost pressures wereachieved rapidly.

Another approach is described in JP 59-99028. This system uses acompressed-air injecting port receiving air from a compressed-air tank,where the port was formed in a valve seat of the intake valve, and saidport is opened when the intake valve is opened. An on-off valve isopened transiently for a prescribed period when an accelerator pedal israpidly depressed. When the intake valve is open, air is injectedthrough the valve seat for supplementing lack of air caused transientlywhen the accelerator pedal is depressed. Specifically, when theaccelerator pedal depression signal exceeds a prescribed value, theon-off valve is opened by a computer for a prescribed periodcorresponding to the pedal depressing speed. With such a system, boostcompensation is allegedly unnecessary.

However, the inventors herein have recognized disadvantages with each ofthe above approaches. For example, if using the storage approach of SAE670109 on an otherwise naturally aspirated engine, boost was providedfor only a limited time since storage tanks were the only source ofcompressed air. Further, the system required two tanks of about 12inches in diameter each, thus requiring significant packaging space inthe vehicle.

Likewise, regarding the approach in the abstract of JP 59-99028,significant air-fuel ratio control errors may be encountered if such asystem were applied to a gasoline engine. Specifically, the additionalair provided by the boost system may not be measured by a manifoldpressure sensor or mass airflow sensor in the intake manifold, and thusthe amount of fuel supplied may not match the total inducted airflow,resulting in an air-fuel ratio excursion. Furthermore, it does notappear that the energy of compression of the added air is used toamplify air flow through the main intake port. This means that thecompressed air tank must be large enough to supply all of the desiredincrease of intake air mass.

Thus, in one approach, the above disadvantages may be overcome by asystem for a vehicle traveling on the road. The system comprises: anengine having at least a cylinder; a fuel injector coupled to saidcylinder; a compression device coupled to said engine; a compressed airstorage device coupled to said compression device and configured todeliver compressed air to said cylinder through an air amplifier device;and a controller to adjust an amount of fuel injection to account forvariation of compressed air delivered to said cylinder from saidcompressed air storage device.

In this way, it is possible to provide accurate fueling amounts, evenwhen unexpected changes in an amount of compressed air are encounteredbefore or during an intake event. Further, the ability to provide rapidresponse to variations in delivered compressed air enables furtherexploitation of the ability to accommodate the earliest possibleinduction of such compressed air, thereby further increasing enginetransient responsiveness.

Note that various types of fuel injectors may be used, such as sidedirect injection, overhead direct injection, and port injection.

DESCRIPTION OF THE FIGURES

FIGS. 1-3 are each a schematic diagram of an engine;

FIG. 4 shows a schematic diagram of an example air storage system thatmay be used with various types of engines, such as those in FIG. 1-3;

FIGS. 5-7 show example embodiments of ejector systems that may be usedwith the storage system of FIG. 4;

FIGS. 8-10 show high level flowcharts of example engine operation; and

FIG. 11 shows a graph illustrating available time for fuel injection.

DETAILED DESCRIPTION

As noted above, the present application describes an approach thatprovides boost compensation to reduce effects of compressor delays, suchas the phenomena known as turbo-lag, as well as improve various otherengine operations, such as engine cold starting. In one particularexample, a separate source of compressed air is available to be rapidlysupplied to the engine (e.g., via the intake manifold, intake port, orcylinder head) during selected conditions, such as in response to anaccelerator pedal tip-in, thus reducing turbo-lag. The additional airfrom the air amplifier serves to provide a rapid increase in cylindercharge, even when the turbocharger has not yet attained sufficient speedto generate the desired pressure boost. Furthermore, the injection ofhigher pressure air into the engine cylinders results in an almostimmediate increase in exhaust flow, which enhances function of theturbocharger, and thus can further reduce the turbo-lag period. In otherwords, it is possible to create more flow into the cylinder than whatcomes from a compressed air source, but in one example, this air flowamplification is implemented only until the turbocharger comes up tospeed.

In one example, the separate compressed air supply may be providedupstream of the engine between the engine air filter and the intakemanifold, either before of after the turbocharger. Alternatively, thecompressed air could be supplied in the intake manifold or cylinderhead. Further, an ejector may be used to create an ejector boost system.For example, an ejector may be integrated into a valve seat to furtherimprove operation. In still another example, the system may be appliedin direct injection gasoline engines to achieve improved air-fuel ratiocontrol, or applied to improve engine cold starting of gasoline ordiesel engines.

In this way, it is possible to utilize an air source in combination witha flow amplifier device to provide improved operation for an engineusing gasoline, diesel, or various other fuel types.

Referring now to FIG. 1, internal combustion engine 10, comprising aplurality of cylinders, one cylinder of which is shown in FIG. 1, iscontrolled by electronic engine controller 12. Engine 10 includescylinder head 46, combustion chamber 30 and cylinder walls 32 withpiston 36 positioned therein and connected to crankshaft 40. Combustionchamber 30 is shown communicating with intake manifold 44 and exhaustmanifold 48 via respective intake valve 52 and exhaust valve 54. Eachintake and exhaust valve may be operated by a camshaft, or both may beoperated by a common camshaft. Variable valve timing operation may beused via a hydraulic actuator. In an alternative embodiment, the valvesmay be operated by an electromechanically controlled valve coil andarmature assembly.

Cylinder 30 is also shown having direct fuel injector 65 coupled theretofor delivering liquid fuel in proportion to the pulse width of signalFPW from controller 12 via a fuel injection system 87, which may be ahigh pressure common rail diesel fuel system. Fuel system 87 may includea fuel tank, high and low pressure fuel pumps, and a fuel rail (notshown). The engine 10 of FIG. 1 is configured such that the fuel isinjected directly into the engine cylinder, which is known to thoseskilled in the art as direct injection. In addition, intake manifold 44is shown communicating with optional electronic throttle 125.

Engine 10 is also shown coupled to a turbocharger system 130, which isone example compression device that may be used. Turbocharger system 130includes a compressor 132 on the intake side and a turbine 134 on theexhaust side coupled via a shaft 136. In an alternative embodiment, atwo-stage turbocharger may be used, if desired. In another alternativeembodiment, a supercharger may be used having a compressor similar to132 that is driven via the engine crankshaft 40.

Universal Exhaust Gas Oxygen (UEGO) sensor 76 is shown coupled toexhaust manifold 48 upstream of turbine 134 and emission control device70. Device 70 may be a NOx catalyst, an SCR (selective catalyticreduction) catalyst, a particulate filter, or combinations thereof. Asecond exhaust gas oxygen sensor 98 is shown coupled to the exhaustsystem downstream of catalytic converter 70. Emission control devicetemperature is measured by temperature sensor 77, and/or estimated basedon operating conditions such as engine speed, load, air temperature,engine temperature, and/or airflow, or combinations thereof.

Controller 12 is shown in FIG. 1 as a conventional microcomputerincluding: microprocessor unit 102, input/output ports 104, andread-only memory 106, random access memory 108, keep alive memory 110,and a conventional data bus. Controller 12 is shown receiving varioussignals from sensors coupled to engine 10, in addition to those signalspreviously discussed, including: engine coolant temperature (ECT) fromtemperature sensor 112 coupled to cooling sleeve 114; a position sensor119 coupled to an accelerator pedal; a measurement of engine manifoldpressure (MAP) from pressure sensor 122 coupled to intake manifold 44; ameasurement (ACT) of engine air charge temperature or manifoldtemperature from temperature sensor 117; and an engine position sensorfrom a Hall effect sensor 118 sensing crankshaft 40 position. In apreferred aspect of the present description, engine position sensor 118produces a predetermined number of pulses every revolution of thecrankshaft from which engine speed (RPM) can be determined.

In some embodiments, the engine may be coupled to an electricmotor/battery system in a hybrid vehicle. The hybrid vehicle may have aparallel configuration, series configuration, or variations orcombinations thereof.

Engine 10 further has a pressurized air delivery system for deliveringhigher pressure air to the combustion chamber, an example of which isdescribed in more detail below herein with regard to FIG. 4.

FIG. 2 shows an alternative embodiment of a gasoline direct injectionengine 11 similar to that of FIG. 1. In the example of FIG. 2, cylinderhead 46 is shown having fuel injector 66 coupled thereto for deliveringliquid fuel in proportion to the pulse width of signal FPW fromcontroller 12. Fuel is delivered to fuel injector 66 by a fuel system(not shown) including a fuel tank, fuel pump, and fuel rail (not shown).In one example, a low pressure direct injection system may be used,where fuel pressure can be raised to approximately 20-30 bar.Alternatively, a high pressure, dual stage, fuel system may be used togenerate higher fuel pressures. FIG. 2 also shows distributorlessignition system 88 providing ignition spark to combustion chamber 30 viaspark plug 92 in response to controller 12.

Continuing with FIG. 2, it shows catalytic converter 72, which caninclude multiple catalyst bricks, in one example. In another example,multiple emission control devices, each with multiple bricks, can beused. Converter 72 can be a three-way type catalyst in one example.

Engine 11 also has a pressurized air delivery system for deliveringhigher pressure air to the combustion chamber, an example of which isdescribed in more detail below herein with regard to FIG. 4.

In still another alternative example, engine 9 may be a port injectedgasoline engine. Specifically, FIG. 3 shows still another alternativeembodiment of a gasoline port injection engine 9 similar to that ofFIGS. 1 and 2. In the example of FIG. 3, an intake port of manifold 44is shown having fuel injector 66 coupled thereto for delivering liquidfuel in proportion to the pulse width of signal FPW from controller 12.

Any of engines 9, 10, 11 may be used for road vehicles, boats,earthmoving equipment, airplanes, generators, pumps, etc.

Referring now to FIG. 4, an example air storage system 310 is describedthat may be coupled to engine 9, 10, or 11. Specifically, compressed air312 is directed to the system from a high pressure compression device(such as a compressor (not shown)), through one-way check valve 314 tostorage tank 316. The valve 314 enables flow into tank 316, butrestricts flow from tank 316 to the compression device. Further, in oneexample, system 310 also includes control valve 318, receiving a controlsignal 320 from controller 12, for controlling air via pressureregulator valve 324 to the air amplifier as described in more detailwith regard to the example embodiments of FIGS. 4-6. In this way, it ispossible to supply higher pressure air to the engine even whenturbocharger pressure buildup is delayed due to turbo-lag, for example.Further, by using such a system, it is possible to store compressed airgradually with a smaller compressor, yet provide a large flow rate forshorter intervals of time, as needed to prevent turbo-lag.

The storage pressure in tank 316 may vary depending on the mass of airstored in the tank, but can vary as high as the compressor outputpressure, which may be 1500 psi or higher. However, as the duty cycleusage of compressed air in the engine may be relatively low compared toall engine operation (e.g., during turbo-lag conditions, or enginestarting conditions, for example), a low volume, high pressure,compressor can be used to charge the tank slowly compared to the rate offlow exiting during use.

The pressure regulator 324 is generally set to maintain a pressure ofabout 150 psi, so that air fed to the primary nozzle inlet is generallymaintained at about this pressure, which may be significantly higherthan manifold pressure. As will be described in more detail belowherein, the primary nozzle then uses this compressed air at about 150psi, along with air in the intake manifold (whose pressure may varydepending on the state of the turbocharger, engine speed, throttleposition, etc.) to create increased flow into the engine cylinder.

As noted herein the air amplifier may be referred to as an ejectorassembly, air ejector, air amplifier, and flow amplifier.

Referring now to FIG. 5, a first example embodiment for deliveringhigher pressure air to engine 9, 10, or 11 is described. In thisexample, intake manifold 44 is shown with an intake runner 44 a havingthroat area 44 b leading to intake valve 52 and cylinder 30, with a highpressure tube 410 delivering pressurized air. Specifically, thepressurized air tube 410 is coupled in the intake manifold and includesa supersonic nozzle 412 directed into each intake runner (only one ofwhich is shown). In this way, the manifold plenum serves as an ambientair inlet, the pressurized air tube 410 serves as a primary nozzle, themanifold runner serves as a secondary nozzle, the throat of the port (44b) serves as a mixing tube, and finally the cylinder serves as adiffuser. Such a system may be generated for each cylinder of the engineby placing a nozzle in each intake runner. In this way, it is notnecessary to pressurize the entire plenum volume, resulting in fasterdelivery of boost pressure to the cylinders, and less heat loss to themanifold walls for further improvement of engine cold start.

In example operation, each individual nozzle may be fitted with a valveto synchronize the nozzle flow with intake valve open position, inaddition to control of pressurized air via valve 318. In an alternativeembodiment, the plurality of nozzles may be controlled via a singlevalve.

Referring now to FIG. 6, a second example embodiment for deliveringhigher pressure air to engine 9, 10, or 11 is described. Specifically,FIG. 6 shows a sectional view of a second example embodiment fordelivering higher pressure air to engine 9, 10, or 11. In this example,intake manifold runner 44 a is shown leading to intake valve 52. Valve52 seats against a unitary valve insert/seat 512 located in cylinderhead 510. Insert 512 includes a port portion 520 and a head portion 522.Insert 512 includes an annular supersonic nozzle 514 formed in insert512. The nozzle may have a converging-diverging shape as shown in FIG.6. Pressurized air may be delivered via one or more delivery tubes 530to the annular nozzle 514.

In this way, it is possible to incorporate a supersonic nozzle into thecylinder head, with at least one nozzle at each cylinder. When theintake valve is closed, as shown in FIG. 6, the pressurized air outletis blocked by the intake valve head. When the intake valve is open, thediverging nozzle formed within the insert directs a supersonic dischargepast the valve head and into the cylinder, thus forming an ejector withan annular supersonic nozzle. Thus, the amount of compressed airconsumed during delivery may be reduced since air is delivered onlyduring operation where the intake valve is open. Further, if acontroller is used to estimate an amount of air delivered via thenozzle, the amount can be estimated based on intake valve opening andclosing timings, as well as cylinder pressure and upstream (e.g.,compressed air supply) pressure. For example, with variable valve timingof either the intake and/or exhaust valves, variation in valve timingmay affect the amount of compressed air delivered, such as in thesystems of FIGS. 6-7, for example. Therefore, the controller may includeroutines for estimating an amount of compressed air that accounts forvariation in valve opening and/or closing timings.

Returning to the structure of FIG. 6, by using a unitary insert, it ispossible to provide a supersonic nozzle with reduced part count, andprovide improved ability to control dimensions allowing improvedtolerancing. Further, structural bridges 524 (see FIG. 6A) may beincluded within the annular nozzle to attach the port and head portionsto each other and to carry the forces of installation into the head andimpact from the closing of the intake valve. The bridges may causeinterruptions in the annularity of the nozzle, but should not causemajor degradation of function. For example, the bridge may be designedwith a length (in the direction of flow) longer than a width, therebyproviding desired structural rigidity while reducing impact on flow.

Referring now to FIG. 7, a sectional view of a third example embodimentfor delivering higher pressure air to engine 9, 10, or 11 is described.In this example, intake manifold runner 44 a is shown leading to intakevalve 52. Valve 52 seats against a 2-piece valve insert/seat 612 locatedin cylinder head 610. Insert 612 includes a port piece (insert) 620 anda head piece (seat) 622. Insert 612 thus forms an annular supersonicnozzle 614 formed in insert 612. Pressurized air may be delivered viaone or more delivery tubes 624 to the annular nozzle 614.

In this way, it is possible to incorporate a supersonic nozzle into thecylinder head, with at least one nozzle at each cylinder. When theintake valve is closed, as shown in FIG. 7, the pressurized air outletis blocked by the intake valve head. When the intake valve is open, thediverging nozzle formed between the two inserts directs a supersonicdischarge past the valve head and into the cylinder, thus forming anejector with an annular supersonic nozzle. Thus, the amount ofcompressed air consumed during delivery may be reduced since air isdelivered only during operation where the intake valve is open. Further,if a controller is used to estimate an amount of air delivered via thenozzle, the amount can be estimated based on intake valve opening andclosing timings, as well as cylinder pressure and upstream (e.g.,compressed air supply) pressure.

Referring now to FIG. 8, a first example embodiment of a routine forcontrolling engine operation to reduce turbo-lag is described. In thisexample, which may be a diesel or gasoline engine, the routine firstdetermines engine operating conditions in 710, such as engine speed,engine load, throttle position, intake manifold absolute pressure,engine temperature, storage pressure of tank 316, temperature of tank316, turbine/compressor speed, and others.

Then, in 712, the routine determines whether an accelerator pedal tip-inhas occurred under conditions in which turbo-lag may exist. For example,this may occur during lower turbine speed conditions, or low massairflow conditions. If so, the routine continues to 714 to determinewhether compressed air is available, for example, in response topressure in tank 316. Further, a need for additional compressed air mayalso be based on other indications, such as a desired engine torque, arate of change of desired torque, a driver demanded torque, etc. Inaddition, or in the alternative, an indication may also be generatedthat additional compressed air is desired during engine cold starting.For example, a boost of cylinder inlet pressure may result in highercompression temperatures in the combustion chamber and serve to improveengine cold starting combustion, especially for a diesel engine.

If pressurized air is available, the routine continues to 716 todetermine an amount of compressed air to add and/or a duration ofcompressed air addition. For example, under some conditions, it may beadvantageous to provide compressed air for a first number of combustionevents, or until a selected turbine speed is reached, while under otherconditions, it may be advantageous to provide compressed air for alonger duration or a greater number of combustion events, or to a higherturbine speed. Further, the routine activates valve 320 to makecompressed air available to the ejector system.

Next, in 720, the routine determines if the duration (or other measure)of 716 has elapsed, thus indicating the additional supply of air is nolonger desired. If so, the routine continues to 718 to deactivatecompressed air addition, e.g., by deactivating valve 320. Otherwise, theroutine continues to 722 to add compressed air to the engine'scylinders. For example, the routine may control additional valves (ifpresent) to control the timing of addition of compressed air, or mayrely on a valve insert ejector system, as described herein.

In this way, it is possible to supply additional air when needed tocompensate for turbo-lag. Further, the ejector may be used only for theduration of turbo-lag period, thus reducing the size of compressed airstorage needed.

It should be noted that during the period of air injection at 722,before the desired duration of injection that was calculated at 716 hasbeen determined at 720 to have elapsed, the operating conditions andaccelerator pedal tip-in status are continually being monitored at 710and 712. If there is a change of conditions, such as a driver “change ofmind” with the desired load being rapidly reduced, a new calculation ofdesired duration will be sent to 720 to possibly override a priordecision.

Referring now to FIG. 9, a second example embodiment of a routine forcontrolling engine operation to reduce turbo-lag is described. In thisexample, which may be a diesel or gasoline engine, the routine firstdetermines engine operating conditions in 810, such as engine speed,engine load, throttle position, intake manifold absolute pressure,engine temperature, storage pressure of tank 316, temperature of tank316, turbine/compressor speed, and others. Then, in 812, the routinedetermines whether a tip-in or other condition indicative of a possibleturbo-lag, or desire for compressed air, is present. For example,compressed air may aid cold start performance, especially for a dieselengine. Also, as noted with regard to 812, other parameters and factorsmay also be used. If the answer to 812 is yes, the routine continues to814 to determine an amount and/or duration of compressed air to add inresponse to operating conditions, such as those determined in 810. Then,in 816 the routine adds the extra air to the cylinders as noted abovewith regard to FIG. 8.

Then, the routine determines a fuel amount adjustment based on theaddition of pressurized air. Further, the routine may also determine aninjection timing adjustment as different fuel injection timing may beused when adding pressurized air from the injection timing withoutpressurized air. In the example of a gasoline engine where air-fuelratio is controlled to a desired value, such as about stoichiometry, theroutine may determine a fuel adjustment amount to match the additionalair due to the pressurized air addition and thereby maintain a desiredair-fuel ratio.

Next, in 820, the routine determines whether multiple injection may beused, which may be based on whether pressurized air is added, and otheroperating conditions. The use of multiple injections may be used toprovide faster fuel injection later in the induction stroke, rather thanwaiting for later fueled cylinder events to match added air. If theanswer to 820 is yes, the routine continues to 822 to select therelative amount of fuel and timing between the multiple injectionevents. Then, in 824, the routine delivers the desired fuel injection(or injections) at the selected timing (or timings).

In this way, it is possible to coordinate fuel injection amounts and/ortiming with the addition of pressurized air to reduce the effects ofturbo-lag, while maintaining desired air-fuel ratio.

Note that the routine may determine the amount of pressured air addedbased on various factors, such as manifold pressure, pressure in tank316, intake valve timing, and others. In addition, or in thealternative, the routine may use pressure sensors or a mass airflowsensor to measure the amount of air from the ejector system.

Referring now to FIG. 10, a routine is described for controllingpressure of compressed air delivered to the ejector assemblies. Theroutine first reads operating conditions in 910, such as temperature,manifold pressure, etc., and then determines a desired delivery pressurein 912 based on the operating conditions of 910. Then, the routineadjusts a parameter, such as an adjustable pressure regulator valve, toachieve the desired delivery pressure. In this way, higher pressure maybe supplied under conditions where higher ejector flow is desired, orwhere valve opening time is shortened.

Note that there may be conditions where it could be possible to addadditional air via the ejector assembly, but not possible to providematching additional fuel. Under such conditions, delivery of theadditional air may be delayed until matching fuel can also be provided,such as under stoichiometry control in gasoline engines.

Referring now to FIG. 11, a graph illustrates the advantageous operationof using direct fuel injection with an ejector compensation system suchas described above herein. Specifically, the graph illustrates theadditional interval (from x1 to x2) available to provide extra fuelinjection to compensate for the additional air from the ejector with adirect injection system as compared with a port injection system withclosed valve injection.

For example, assuming a tip-in occurs at the point located, if usingport fuel injection, it may not be desirable to add the compressed airfor the upcoming cylinder whose valve timing is shown (since theinjection of additional fuel also takes a certain amount of time).However, if direct fuel injection is used, and the fuel injectionduration is lengthened (or a second injection is used), for example, itmay still be possible to compensate the fuel injection for theadditional air, and thus the additional air and fuel may be provided forthe cylinder shown. Such operation may enable a faster response to thedriver tip-in, while still maintaining a desired combustion air-fuelratio. In this way, even if an unexpected driver tip-in occurs, it isstill possible to adjust the fuel and air of a cylinder soon to befired.

It will be appreciated that the processes disclosed herein are exemplaryin nature, and that these specific embodiments are not to be consideredin a limiting sense, because numerous variations are possible. Thesubject matter of the present disclosure includes all novel andnon-obvious combinations and subcombinations of the various camshaftand/or valve timings, fuel injection timings, and other features,functions, and/or properties disclosed herein.

Furthermore, the concepts disclosed herein may be applied to multi fuelengines capable of burning various types of gaseous fuels and liquidfuels.

As still another example, the particular location of sensor measurementsmay be varied and/or modified. For example, ACT may be measured before aturbocharger compressor and MAP measure after the compressor. Suchmeasurement locations may be particularly advantageous in that the MAPthat can be more influential to some operation of the cylinder(s) is thedownstream pressure, and the ACT sensor may have a time lag that wouldmake it inaccurate during transients where the boost pressure andresulting temperature is rapidly changing. Thus, placing the ACT sensorbefore the compressor may remain more stable.

In another embodiment, a spark advance strategy on a gasoline engine maybe adjusted to account for pressurized air delivery. For example, duringejector function, the controller may adjust spark advance in an at leastpartially open loop manner to accommodate rapid transient conditionssince sensor time lags may be significant. In this way, engine knockthat may other occur can be reduced or avoided during delivery therebyachieving improved performance.

The following claims particularly point out certain combinations andsubcombinations regarded as novel and nonobvious. These claims may referto “an” element or “a first” element or the equivalent thereof. Suchclaims should be understood to include incorporation of one or more suchelements, neither requiring nor excluding two or more such elements.Other combinations and subcombinations of the injection and temperaturemethods, processes, apparatuses, and/or other features, functions,elements, and/or properties may be claimed through amendment of thepresent claims or through presentation of new claims in this or arelated application. Such claims, whether broader, narrower, equal, ordifferent in scope to the original claims, also are regarded as includedwithin the subject matter of the present disclosure.

1. A boost system for an engine, comprising: an engine having at least a cylinder; a fuel injector coupled to said cylinder; a compression device coupled to said engine; a compressed air storage device coupled to said compression device and configured to deliver compressed air to said cylinder through an air amplifier device; and a controller to adjust an amount of fuel injection to account for variation of air mass delivered to said cylinder through said air amplifier device.
 2. The system of claim 1 wherein said air amplifier device is an air ejector assembly, used by itself or in conjunction with a turbocharger or supercharger.
 3. The system of claim 1 wherein said air amplifier device is an air ejector assembly, and wherein said injector is a direct injector.
 4. The system of claim 3 wherein said controller further adjusts an amount of said air mass delivered in response to a desired output demand.
 5. The system of claim 3 wherein said controller further adds at least some fuel from said direct fuel injector after intake valve closing of said cylinder to account for additional air entering said cylinder.
 6. The system of claim 3 wherein said controller further adjusts said amount of fuel in response to an exhaust gas oxygen sensor.
 7. The system of claim 6 wherein said controller varies an air flow produced by said air amplifier device in response to variation in operating conditions.
 8. The system of claim 3 wherein said controller determines said fuel amount in response to air flow through said air amplifier device.
 9. The system of claim 1 wherein said air flow delivered to said cylinder is delivered by an ejector assembly using a primary nozzle built into a valve seat.
 10. The system of claim 1 wherein said injector is a direct injector, and wherein said controller initiates multiple injections during a cycle of said cylinder to deliver said amount of fuel injection.
 11. The system of claim 10 wherein a first injection is performed at least partially during an intake stroke, and a second injection is performed after said first injection, and at least partially after intake valve closing of said cylinder.
 12. The system of claim 10 wherein a first injection is performed at least partially during an intake stroke, and a second injection is performed after said first injection, and at least partially during an early part of a compression stroke.
 13. A boost system for an engine, comprising: an engine having at least a cylinder; a fuel injector coupled to said cylinder; an air amplifier device coupled into the air passageway to said cylinder; a compression device coupled to said engine; a compressed air storage device coupled to said compression device and configured to selectively deliver compressed air to said air amplifier device; and a controller to determine an amount of air entering said cylinder during said selective delivery of said compressed air to the air amplifier and to adjust an amount of fuel injection to account for Increase of said air mass inducted into said cylinder, and thereby maintain a desired air-fuel ratio about stoichiometry.
 14. The system of claim 13 wherein said controller estimates an amount of additional fuel to add based on an air amplifier inlet pressure, engine speed, and intake manifold pressure.
 15. The system of claim 13 wherein timing of said selective delivery is controlled by cylinder intake valve timing and position.
 16. The system of claim 15 further comprising a valve seat insert, and wherein said compressed air is delivered to said insert.
 17. The system of claim 16 wherein said insert includes a converging-diverging nozzle.
 18. A method for controlling engine operation of an engine having a turbocharger, a compressed air storage system coupled to said engine, said system selectively providing enhanced air flow to cylinders of the engine, the method comprising: during a driver tip-in event under conditions where said turbocharger is operating below a selected threshold, selectively providing said compressed air to the cylinder and adjusting a fuel injection amount to maintain a desired air-fuel ratio, where said fuel injection is delivered in at least two separate injections during a cylinder cycle at least for one cylinder cycle.
 19. The method of claim 18 wherein said engine is a gasoline engine, and wherein said compressed air is provided through an air flow amplifier system coupled to the engine.
 20. The method of claim 19 wherein said selective providing of compressed air is performed through a converging-diverging nozzle in a valve seat.
 21. A boost system for an engine, comprising: an engine having at least a cylinder; a direct fuel injector coupled to said cylinder; a turbocharger device coupled to said engine; a compressed air storage device coupled to said engine and configured to selectively deliver compressed air to said cylinder; an air flow amplifier device coupled to the inlet air passageway to said cylinder, wherein said compressed air storage device is configured to selectively deliver compressed air through said flow amplifier device; and a controller to adjust a timing of direct fuel injection when delivering compressed air to said cylinder from said compressed air storage device. 